It's so interesting to read all the different thoughts flying around why people correct, and peoples' reaction to being corrected.
I'm someone who enjoys having my own typing/grammar errors pointed out, but that's because I see it as a skill I take pleasure in improving, and I don't have any condition that makes me particularly insecure about being corrected.
I appreciate it the same way I'd appreciate someone pointing out a better technique for a particular bit of painting, for example.
However, I dont' correct others because I've learned that genuinely other people don't feel the same way (it took me a long time to learn this!) I do have social communication issues myself, which may be responsible for a little empathetic blindness in me. There's no emotion or judgement attached to spelling/grammar corrections for me (giving or receiving), and although I understand other people reporting these reactions, I can't pretend to understand them... at all.
I've also come to realise that some people perhaps do have malicious reasons for correcting others (ie. to deliberately invoke feelings of distress). Just thought it's worth pointing out that this is by no means automatically the intention (as it never would have been from me), sometimes people may be doing it out of genuine incomprehension of how it may be received.
I suppose this is quicker/slower to learn depending on the 'correcter's' own social insight or any other inhibiting difficulties.